Ioan,
The Component vendor data sheets are good for just the things you
mentioned: Max temp component can withstand, and max slope (rise &
fall) the component can withstand. The best total profile information
will come from your solder paste vendor. They will provide a total
"recommended best" profile for their paste. some like a "knee" in the
soak zone, but many newer formulations no longer need the knee. This
is good since the more you reduce the soak time requirements, the
faster your profile (and thru-put!!). Anyway, call yer local paste
vendor for theie recommendations. If you compare paste vendors
profiles, they are all getting to be close to the same anymore. I use
the same reflow profiles on 3 different vendors NC pastes, and they
all perform very well. The "Profiling Basics" still hold true for most
good paste formulations.
Good luck and regards,
Jeff Hempton
United Technology Electronic Controls.
______________________________ Forward Header __________________________________
Subject: [TN] Reflow profile
Author: "Tempea; Ioan" <[log in to unmask]> at Internet
Date: 5/18/1999 9:35 AM
Hi everybody,
I saw a lot of discussions around problems that show on finished assemblies.
This includes splashing, voiding, opens.
In the end all this comes to one Big Daddy, that is reflow profiling.
My question is: does anybody know a place in the cyber world (I'd rather go
for this) or in the vast SMT libraries where a reference profile is shown
and all the steps are thoroughly explained?
You know, that kind of profile I see in the data sheets every time we get a
new component. The only problem is these ones are very slim, they only say
this is the soak area, if you are below line you get splattering or voiding,
if you are above you burn the board, try to be under 215C for the top of
component, slope 2-4C, etc.
Me, I need to know what happens in each area, what are the ranges of the
temperatures and slopes, if one changes one parameter, like temperature or
time, what will happen and so on.
By the way, I'm using a convection reflow oven and, for the brothers in
Europe, I'm located in Montreal, Canada.
Regards, Ioan
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